Hose doesn't fit new vacuum head

[ronwell]

New home with vinyl-liner pool came with a vacuum head for concrete pools (rectangular w/ wheels). I bought a triangular vacuum head for a vinyl liner from Lowes. The coupling on the new head looks and measures the same as the one on the old vacuum head, but when connecting the hose to the new head it doesn't have enough friction to grip. The outside diameter of the new head coupling is the tiniest bit smaller than the old one.

I don't want to buy a new hose.

I am going to try to find some kind of hose adapter or collar or thick rubber band to put on the new vacuum head coupling to produce enough friction with the hose to hold it on.

Anyone else dealt with this?

Some photos of the type of heads I'm dealing with.

 

[Kiss4aFrog]

I've had an issue as my hose is older and I think it's lost some grip as the rubber/vinyl has relaxed. I ended up using a stainless steel hose clamp as I was tired of it coming off on me.
They have them with a wing on them so it's easily removable without tools.

Auto parts stores, maybe big box too. MasterPro Hose Clamps MP5Y028V - Hose Clamp With Tightening Key | O'Reilly Auto Parts

 

[ronwell]

My hose has hard plastic, unflexible fittings on the ends. I'd have to cut those off to use a hose clamp. I don't want to do that, nor fool with hose clamps each time I vacuum.

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Other ideas I had were some sort of water proof tape passed around the vacuum head coupling to increase it's outside diameter or layer of caulk around it (but this could get messy).

 

[sargent]

Drill a hole through the fitting and vacuum. Run a short screw through to hold them together.

 

[ronwell]

Wrapped w/ duct tape and got it to fit snug.